Trench Collapse - Factors to consider
To prevent injury or death due to collapse of trenches, employers should also ensure there is a safe way to enter and exit the trench, keep materials away from the edge of the trench and look out for water hazards.
Five construction workers in Narok County survived narrowly after a a sewer trench they were digging caved in on the morning of October 13, 2020.
The five who are employees of a Chinese construction company contracted to conduct works on the Narok town sewerage project. The project is part of the Kenya towns sustainable water supply and sanitation programme funded by the government and the African Development Bank.
A trench collapse happens for a number of reasons. Sometimes, the fact that the soil around the trench is dry or is of a material that does not naturally hold together well can lead to an unexpected collapse. Wet weather and the vibrations from nearby construction equipment can also cause a collapse. Preliminary investigations in the Narok incident established that the walls of the trench collapsed due to loose soil as a result of rains.
According to OSHA, excavations refer to any man-made cavity, trench or depression on the surface that resulted from earth removal. A trench is the result of an excavation and which is deep and 15 feet wide. Trench collapse is a hazard that few contractors take seriously since most don’t take the weight of soil into account. When a trench caves in unprotected workers are buried under that mass instantly which can prove fatal.
To prevent injury or death due to collapse of trenches, employers should also ensure there is a safe way to enter and exit the trench, keep materials away from the edge of the trench and look out for water hazards. Employees are also cautioned never enter a trench unless it has been properly inspected.